Hardening resins with CO2 gas known as carbofen or PROCARB is another very useful new product for muscle and mold production that can be used to increase production quality and reduce costs. Carbofen is a type of organic adhesive that, without affecting the sintering point of sand, in addition to reducing sand burning defects, has a significant effect on reducing gas defects, etc. The muscle and mold produced with Carbofen resin has a higher surface smoothness and its excellent degradability after melting leads to a significant reduction in personnel costs.